Process for breaking petroleum emulsions



l atent ed July l, 1952 PROCESS FOR BREAKING PETROLEUM EMULSIONS MelvinDe Groote, University City, Mo., assignor to Petrolite Corporation,Ltd., Wilmington, Del, a corporation of Delaware No Drawing. ApplicationMarch 5, 1951,

SerialNo. 214,003

9 Claims.

This invention relates to petroleum emulsions of the water-.in-oiltype-that are commonly referred to as cut oil, roily oil, emulsifiedoil, etc., and which comprises fine droplets of naturally-occurringwaters or brines dispersed in a more or less permanent state throughoutthe oil which constitutes the, continuous phase of the emulsion.

One object of my invention is to provide a novel process for breaking orresolving emulsions of the kind referred to.

Another object of my invention is to provide an economical and rapidprocess for separating emulsions which have been prepared undercontrolled conditions from mineral oil, such as crude oil andnrelativelysoft waters or weak brines. Controlled emulsification and subsequentdemulsiiication under the conditions just mentioned,

are of significant value in removing'impurities.

particularly inorganic salts from pipeline oil.

Demulsification as contemplated in the present application includes thepreventive step of commingling the demulsifier with the aqueouscomponent which would or might subsequently become either phase of theemulsion, in absence of such precautionary measure. Similarly, suchdemulsifier may be mixed with the hydrocarbon component.

The demulsifying agent employed in the present process is a fractionalester obtained from a polycarboxy acid and a diol obtained by theoxypropylation of a dihydroxy ether of glycerol.

This glycerol ether is obtained by reacting one mole-of diethyleneglycol monoethyl ether,

with one mole of glycid, or any comparable procedure which produces thesame compound or equivalent isomer thereof. Diethylene glycol monoethylether can be prepared in any suitable manner and can be purchased. Mypreference is to treat the glycerol ether of diethylene glycol monobutylether with suiiicient propylene oxide so that the resultingproduct isnot completely water-soluble, i. e., is at least emulsifiable orinsoluble in water, and also so the product is no longer completelyinsoluble in kerosene, i. e., tends to disperse or is soluble inkerosene. Needless to say, the upper molecular weight subsequentlydescribed involves products which are completely water-insoluble andcompletely kerosene-soluble as difierentiated from dispersibility oremulsifiability. It is to be noted that the original glycol itself, i.e., diethylene glycol monoethyl ether, and also the dihydroxy compoundobtained by reaction with glycerol monochlorohydrin or glycide iswater-soluble. Similarly the initial compounds, 1. e., either themonohydroxylated compoundor the dihydroxylated compound priorto'oxypropylation is kerosene-insoluble. In the hereto appended claimsreference to the product being water-insoluble means lack of solubilityeither by being only dispersible, emulsifiable, or rapidly settling outin layers, or for that matter completely insoluble in the usual sense.The intention is to differentiate from an ordinary soluble substance.Similarlyreference in the claims to being at least kerosene-dispersiblemeans that the product will at least disperse or emulsify in kerosene ormay be completely soluble in kerosene to give a clear, transparent,homogeneous solution.

As stated, the monohydric alcohol has the following structure:C2H5OCH2CHzO-CH2CH2OH. Llhe glycide derivative is of the followingstrucure:

C HsOOHgCHiO HgCHgO CQHB with the proviso that 'n and n representwholenumbers which added together equal a sum varying from 15 to 8'0, and theacidic ester obtained by reaction of the polycarboxy acid may beindicated thus:

in which the characters have their previous signlflcance, and n is awhole number not over 2 and R. is the radical of the polycarboxy radicalCOOH i and preferably free from any radicals having more than 8uninterrupted carbon atoms in a single group, and with the furtherproviso that the parent'diol prior to esterification be prefer-f ablywater-insoluble or water-dispersible, and

kerosene-soluble or kerosene-dispersible.

Attention is directed to the co-pending application of C. M. Blair, Jr.,Serial No. 70,311, filed January 13, 1949, now Patent 2,562,878, grantedatoms, and in which the molecular weight of the product is between 1,500to 4,000.

Similarly, there have been used esters of dicarboxy acids andpolypropylene glycols in which 2 moles of the dicarboxy acid ester havebeen reacted with one mole of a polypropylene glycol having a molecularweight, for example, or 2,000 so as to form an acidic fractional ester.Subsequent examination of what is said herein in comparison with theprevious example as well as the hereto appended claims will show theline of delineation between such somewhat comparable compounds. Ofgreater signficance, however, is what is said subsequently in regardto-the structure of the parent diol as compared to polypropyl enegly'cols whose molecular weights may vary from 1,000 to 2,000.

For convenience, what is said hereinafter will be divided into fiveparts:

Part 1 will be concerned with the preparation of the diol by reactingdiethylene glycol monoethyl ether with glycide or its equivalent;

Part 2 will be concerned with the oxyprop'ylation of the diol obtainedin the manner previously described in Part 1;

Part 3 will be concerned with the preparation of esters from theaforementionedv oxypropylation derivatives;

Part 4 will be concerned with the structure of the herein describeddiols and their significance in light of what is said, subsequently;

Part 5 will be concerned with the use of the products herein describedas demulsifiers for breaking water-in-oil emulsions;

PART 1 As previously pointed out the monohydric compoundC2H5OCH2CH2OCH2CH2OH can be prepared in the customary manner orpurchased in the open market. Such compound is then reacted with asuitable reactant, such as glycide, to

give a dihydroxy compound. This reaction may As far as forming thedihydroxy compound is concerned other reactions can be employed which donot involve glycide; for example, one can produce esters of the kindherein employed by use of 2. glycerol monochlorohydrin', i. e., eitheralpha or beta glycerol monochlorohydrin. Attention is directed again tothe fact that in the previous formula and in the formulas inthe claimsit would be immaterial whether the free hydroxyl radicals prior toesterification'are present as attached to the first and third terminalcarbon atoms, or second and third carbon atoms. This is simply anisomeric difierence depending on how the epoxy ring is ruptured in thecase of glycide, or whether one employs glycerol alphav monochlorohydrinor glycerol betamonochlorohydrin. Other suitable procedure involves theuse of epichlorohydrin in a conventional manner. For instance, theoxypropylated compound can be treated with epichlorohydrin and theresultant product treated with caustic soda so as to reform theepoxy-ring. The epoxid so obtained can then be treated with water so asto yield a compound having two hydroxyl radicals attached to. two of thethree terminally adjacent carbon atoms.

Attention is directed to the fact that the use of glycide requiresextreme caution. This is particularly true on any scale other than smalllaboratory or semi-pilot plant operations.

Purely from the standpoint of safety in the handling of glycide,attention is directed to the following:

. (a) If, prepared from glycerol monochlorohydrin,

this product should be comparatively pure; (b)

the glycide itself should be as pure as possible as the efiect ofimpurities is difiicult to evaluate; (c) the glycide should beintroduced carefully and precaution should be taken that it reacts aspromptly as introduced, 1. e.; that no excess of glycide is allowed toaccumulate; (d) all necessary precaution should be taken that glycidecannot polymerize per se; (6) due to the high boiling point of glycideone can readily employ a typical separatable glass resin pot asdescribed in U. S. Patent No. 2,499,370, dated March 7, 1950,-to DeGroote and Keiser, and offered for sale by numerous supply laboratoryhouses. If such arrangement is used to prepare laboratory-scaledwplications, then care should be taken that the heating mantle can beremoved rapidly so as to allow for cooling; or better still, through anadded opening at the top, the glass resin pot or comparable vesselshould be equipped with 'a stainlesssteel cooling coil so that the potcan be cooled more rapidly than by mere removal of mantle. It stainlesssteel coil is introduced it means that the conventional stirrer of thepaddle type is changed into the centrifugal type which causes the fluidor reactants to mix dueto swirling action-in thecenter of the pot. Stillbetter is the use of a laboratory autoclave of the kind previouslydescribed in this part; but in any event when the" initial amount ofglycide is added to a suitable reactant, the speed of reaction should becontrolled by the usual factors, such as (a) the addition of glycide;(b) the elimination of external heat; and (c) the use of cooling sothere is no undue risein tem perature. All the foregoing is merelyconventional but is included due to the hazard in handling glycide.

Escample 1a.

were charged 5 gram-moles of diethylene glycol monoethyl ether. Thisrepresented 670 grams. To this there was added approximately 1% ofsodium methylate equivalent to 7.0 grams. Thetemperature of the reactionmass was raised to 118-? C. 5 moles ,ofglycide, equivalent to' 3'70grams, were added slowly over a period of approximately 6% hours at arate of about 50 grams per hour or slightly less at a gram perminute.Whenever the temperature tended to rise" past C. the reaction mass wascooled; if the temperature showed a tendency to drop below 114 0.110 117C. the reaction mass was heated. When all the 'glycide had been addedthe reaction mass was stirred for approximately one hour longer at C.,and then was heated to" a temperature below the decomposition point ofiglycide, for instance-.140. 0., and. held at: this temperature foranother-hour.- .lnithisparticular'rea'ction. there is less hazard thanisusually the case insofar thatthe amountoi glycide added- Wascomparativeiy small and it .was'added slowly. Even so, suchoxyalkylation could be conducted with extreme care. Other catalysts canbe employed such as caustic soda, or caustic potash,

glycide' itself rather than have it react with the glycol ether. I

, PART 2 For a number of wellknown reason equipment, whether laboratorysize, semi-pilot plant size, pilot plant size, or large scale size, isnot as a rule designed for a particular alkylene oxide. Invariably andinevitably; however, or particularly in the case of laboratory equipmentand pilot plant size the design is such as to use any of the customarilyavailable alkylene oxide, i. e., ethylene oxide, propylene oxide,butylene oxide, glycide, epichlorohydrin, styrene oxide, etc. In thesubsequent description of the equipment it becomes obvious that, it isadapted foroxyethylation' as well as oxypropylation.

Oxypropylations are conducted'under a wide variety of conditions, notonly in regard to presence or absence of catalyst, and the kind ofcatalyst, but also in regard to the time of reaction, temperature ofreaction, speed of reaction, pressure during reaction, etc. Forinstance, oxyalkylations can be conducted at temperatures up toapproximately 200 C. with pressures'in about the same range up to about200 pounds per square inch. They can be conducted also at temperaturesapproximating the boiling point of water OrsIightly above, as forexample 95 to 120 0'. Under such circumstances the pressure will be lessthan 30 pounds per square inch unless some special procedureis employedas is sometimes the case, to wit, keeping an atmosphere of inert' gassuch as nitrogen in the vessel during the reaction. Suchlow-temperature, low reaction rate oxypropylations have been describedvery completely in U. S. Patent No. 2,448,664, to H. R. Fife et al.,dated September 7, 1948. Low temperature, low pressure oxypropylationsare particularly desirable where the compound being subjected tooxypropylation contains one, two or three points of reaction only, suchas monohydric alcohols, glycols and tricls.

Since low pressure-low temperature rea'ction speed oxypropylationsrequire considerable time, for instance, 1 to 7 days of 24 hours each tocomplete the reaction they are conducted as a rule whether on alaboratory scale, pilot plant scale, or large scale, so as to operateautomatically. The prior figure of seven days applies especially tolarge-scale operations. I have used conventional equipment with twoadded automatic features: (a) a solenoid controlled valve which shutsOtherwise, the equipment is substantially .the, 3 same as is commonlyemployed for, this purpose where the pressure of reaction is higher, speed; of reaction ,is higher, and time of reaction, is.

In such instances such automatic,

much shorter. controls. are not, necessarily ,used.

Thus, in preparing the various. exaniplesl have found it particularlyadvantageous to use labora l tory. equipment, or pilot plantwhich isdesigned to permit continuous oxyalky-lation whether itbe ox propylationor oxyethylation. With certain obvious changes the equipment-can be usedalso to permit oxyalkylation involving the use of glycide where nopressure is'involved ,exceptthe, vapor pressure of a. solvent, if any,which may,

have been used as a diluent. 1

As previously pointed out the methodoi;

propylene oxide is the same asethylene oxide.

This point is emphasized only for the reasonthat the apparatus is sodesigned and constructed as to use either oxide.

The oxypropylation procedure employed in the preparation of theoxyalkylated derivatives has been uniformly the same, particularly inlight of the fact that a continuous automatically-con: trolled procedurewas employed. In this pr o-.

cedure the autoclave was a conventional autoclave made of stainlesssteel and having a ca-. pacity of approximately 15 gallons and aworkingpressure of one thousand pounds gauge pressure,

This pressure obviously is far beyond any requirement as far aspropylene oxide goes unless there is a reaction of explosive violenceinvolved due to accident. The autoclave was equipped with theconventional devices and openings, such as thevariable-speed stirreroperating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer welland thermocouple for mechanical thermom-e eter; emptying outlet;pressure gauge, manual vent line; charge hole for initial reactants; atleast one connection for introducing the alkylene oxide, such aspropylene oxide or ethylene oxide, to the bottom of the. autoclave;along with suitable devices for both coolingand heating the autoclave,such as a cooling jacket, and, preferably, coils in addition thereto,with the jacket so' arranged that it is suitable for heating with steamor cooling with water and further equipped.

a separate container to hold the alkylene oxide being employed,particularly propylene oxide. In conjunction with the smallerautoclaves, the con; tainer consists essentially of a laboratory bombhaving a capacity of about one-half gallon, vor somewhat in excessthereof. In some instances a larger bomb was used, to wit, one having acapacity of about one gallon, This bomb was equipped, also, with aninletfor charging, and an eductor tube going to the bottom of the containerso as to permit discharging of alkylene oxide in the liquid phase to theautoclave. A bomb having a capacity of about 60 pounds was used inconnection with the 15-gallon autoclave. Other conventionalequipmentconsists, of course, of the rupture disc, pressure gauge, sightfeed glass, thermometer connection for mtroeenfior pressuring bomb, etc.The bomb was placed 'on a scale during use. The connections between thebomb'and the autoclave were flexible stainless steel hose or tubing sothat continuous weighings could be made without breaking or making anyconnections. This applies also to the nitrogen line, which was used topressure the bomb reservoir. To the extent that it was required, anyother usual conventional procedure or addition which provided greatersafety was used, of course, such'as safety glass protective screens,etc.

Attention is directed again to what has been said previously in regardtoautomatic controls which shut oif the propylene oxide ineventtemperature-of reaction passes out of the predetermined range or ifpressure in the autoclave passes out-of predetermined range.

With this particular arrangement practically all oxypropylations'becomeuniform in that the reaction temperature was held within a vfew degreesof any selected point, cfor instance, if 105 C. was selected as theoperating temperature the maximum point would be at the most 110 C.or-1-1 2 =C.,-and the lower point would be :95

or possibly98 C. Similarly, the pressure "was held at approximately 30pounds within a 5- pound variation one way or the other, but might Idrop to practically zero, especially where no solvent such as xylene isemployed. The speed of. reaction was'comparatively slow under such .con-

ditions as compared with oxyalk-ylations at; 200 C. Numerous reactionswere conducted in which the time varied from one day (24 hours) up toplete in '45'minutes or thereabouts may havebeen complete in a lesserperiod of time inlight of theautomatic equipment used. This applies alsoto larger autoclaves where the reactions werev complete in 9 to 12hours. In the addition of propylene oxide, in 'the autoclaveequipment'as.

far as -possible the valves were set so all the propylene oxide was fedin at a rate so theepredetermined amount reacted in'the first two-thirdsof the selected period; for instance, if the se-.

lected period 'was'3 hours the rate was set so the oxide could be fed inin two hours or less. This means that if thereaction'was interruptedauto matica-lly for a period of time for the pressure to drop, or thetemperature to drop, the-predetermined amount of oxide would stillbeiadded inmost instances well within the predetermined time period. Inone experimcntthe addi-tionoi oxidewas made overa comparati'velylongperiod, i. e., hours. In some instances, of course, the reaction couldbe speeded up to quite a marked degree."

When operating at a comparatively high temperature, for instance,between 150 to 200 0., an 'unreacted alkylene oxide such as propyleneoxide, makes its presence felt in the increase in pressure or theconsistency' o'f a higher pressure. However, at a low enough temperatureit may happen that :the propylene oxide goes inas :a liquid. If so, andif it remains unreacted there is, of course, an inherent dangerandappropriate steps-must -.be taken to safeguard against this possibility;if need be a sample must be withfirawniandsexamined :for unreactedpropylene onlde.: ;;0ne; "obviouslaprocedure; "of. course, is {to.random reaction is decreased. lower the molecular weight the faster thereaction 8 oxypropylateata modestly higher temperature, for instance, atto C'. Unreacted oxide affects determination of the acetyl or hydroxylvalue. of .the'hydroxylated compound obtained.

The high molecular weight of the compound,

1. e., towardsthe latter stages of reaction. the I longer the timerequired to add a given amount of oxide. One possible explanation isthat. the. molecule, being larger, the opportunity for .Inversely, the

takes place. For this reason, sometimesat least,

increasing the concentration of the catalyst does.

not appreciably'speed up the reaction, particularly when the product.subjected to oxyalkylation bomb was so set that when the predeterminedamount of propylene oxide had passed into the reaction the scalemovement through a time operating device was set for either one totwohours so thatreaction continued for 1 /2 to 2 /2 hours after the finaladdition of the last propylene oxide and thereafter the operation wasshut.

down. This particular device is particularly suitable for .use on largerequipment than laboratory size .autoclaves, to wit, on semi-pilot plantor pilot plant. size,.as well as on large scale size. This finalstirring period is intended to avoid the presence of unreacted oxide.

In this sortof operation, of course, the temperature range wascontrolled automatically by either use of cooling water, steam, orelectrical heat, so as to raise or lower the temperature. The pressuringof the propylene oxide into the reaction vessel was also automaticinsofar that the feed stream was set for a slow continuous run which wasshut oil in case the pressure passed a predetermined point aspreviously, set

out. All the points of design, construction, etc., were conventionalincluding the gases, check valves andentire equipment. As far as'I'amaware at least two firms, and possibly three,

specialize in autoclave equipment such as I have employed in thelaboratory, and-are prepared to furnish equipment of this same kind.Similarly pilotjplant equipment'is available. This point is simply-madeas a precaution in the direction of safety. Oxyalky-lations,particularly involvingethylene oxide, glycide, propylene oxide, etc.,should not be conducted except in equipment specifically designed forthe purpose.

Example 1b The dihydroxy compound employed was the one previouslydescribed which, for purpose of convenience, will be termed the glycerolether of diethylene glycol monoethyl ether. The autoclave employed was asmall autoclave having a capacityof approximately onegallon. Thisautoclave was equipped with various automatic devices. In some instancesthe-.oxypropylations were run with automatic controls and inotherinstances, since the oxypropylation was very short, with manual control.Needless-to. say, it was immaterial which way the autoclave was handled.I v v 1 .306 grams of the .dihydroxylated compound previously describedwere charged into the auto- .olave along with 6 grams of caustic soda.It is to be noted that the sodium methylate used in the glycide reactionwas permitted to remain in the reaction mass. This meant that theconcentration of catalyst was slightly higherthan indicated by theamount of caustic added. The reaction pot was flushed out with nitrogen;the autoclave was sealed and the automatic devices adjusted forinjecting 994 grams of propylene 10 oxide in approximately a 6-hourperiod. The pressure regulator was set for a maximum of 35 pounds persquare inch. This meant that the bulkof the reaction could take placeand probably did take place at a comparatively lower All the oxide wasadded in 2Q The initial introduction of oxide was not started until theheating devices had raised the temperature to slightly over 100 C. Whenthe reaction was complete part of the reaction mass was withdrawn as asample and the remainder subjected to further oxypropylation asdescribed in.

Example 21), immediately following.

Example 2b 619 grams of the mixture identified as Example lb, preceding,were reacted with an additional 471.2 grams of propylene oxide withoutadding anymore catalyst. The conditions of reaction were substantiallythe same as in Example lb, preceding, except that the temperature wasslightly higher, i. e., 110 C. instead oi C. The time required to addthe oxide was considerably less than in Example 12), notwithl0 ceding,i. e., a-maximum temperature of C. and; maximum pressure of 35 poundsper square inch. The time required to add the oxide was the same'aspreviously, to wit, 2 hours. The rate of addition was about 200 gramsper hour. At the completion of the reaction part of the reaction masswas withdrawn and the remainder subjected to the final oxypropylationstep as describedin ExampleAb; immediately following.

Example 4%) 400 grams, of the reaction mass identified as Examplesb,preceding, were subjected to further oxypropylation with 133 gramsofpropylene oxide. This was, reacted without the use of any additionalcatalyst. The conditions of reaction as far as temperature and pressurewere concerned were the same as in Examples 212 and 3b, preceding, i.e., 110 0., maximumtemperature and 36 poundsper square inch maximumpressure. The time required to add the oxide was extremely short, towit, less than one hour, more exactly, three-quarters of an hour.

In the hereto attached tables it will be noted that this series showstheoretical molecular weights varying from 1,000 to 4,000, and hydroxylmolecular weights varying from a little less than 900 to a little lessthan 1800. In another series of experiments I proceeded further by threeadditional steps; at amolecular weight corresponding to 5,000theoretical the hydroxyl molecular weight was approximately 2250; at6,000 theoretical molecular weight the hydroxyl molecular weight wasabout 2500, and at 7,000 theoretical molecular weight the hydroxyl.molecular weight was 2650. I have esterified theseparticularoxypropylated' derivativesas well as the ones specificallydescribed" herein.

' 'Whathas been said herein is presented in tabular form in Table 1immediately following, with someadded information as to molecular weightand as to solubility of the reaction product in water, xylene andkerosene.

ABLE 1 Composition Beiore Composition at End M W Ex No l by ig Time n.0. Oxide Cata- Theo.. H. 0. Oxide ,Catag l i lbs. Hrs. Amt., Amt, lyst,M01. Amt, Amt, lyst, er sq. in. grs. grs. grs. Wt. grs. grs. grs. m

306 l. 6 1 003 306 994 6 512 105 35 5 471. 2 2, 8 2: 010 145 1, 090. 2f2. 3 890 110 35 2 70. O 525. 6 1. 4 3, 015 70 823.5 1. 4 1, 415 110 352 31. 2 368.1 64 4, 025 31. 22 501. 1 64 1, 770 110 35 1 The y l' d Cpound is the glycerol ether of diethylone glycol monocthyl ether.

standing .the further dilution of the catalyst.

597 grams or the reaction mass identified as Example 212, preceding,were subjected to further oxypropylation by reaction with 290 grams ofpropylene oxide. This was introduced without any additional catalyst.The conditions of reaction, as far as temperature and pressure wereconcerned, were the same as in Example 2 P tained in this series.

Examples 11) and 2b were soluble in water and xylene, but insoluble inkerosene; and Examples 3b and 4b were emulsifiable to insoluble inwater, soluble in xylene, but dispersible to insoluble in kerosene.

The final product, i. e., at the end of the oxypropylation step, was asomewhat viscous ambercolored fluid which was water-insoluble. This ischaracteristic of all various end products ob- These products were, ofcourse, slightly'alkaline due to the residual caustic soda employed.This would also be the case if sodium methylate were used as a catalyst.

Speaking of insolubilityin water or solubility in kerosene suchsolubility test can tantalisinply by shaking small amounts of thematerials .in a test tube with-water, for instance, using 1% to 5%approximately based on the amount of water present.

Needless to say, there is no complete conversion of propylene oxide intothe desired hydroxylated compounds. This is'indicated by the fact thatthe theoretical molecular weight based on a statistical average isgreaterthan the molecular with a high degree of accuracy when themolecular weights exceed 2,000. In some instances the acetyl value orhydroxyl valueserves as satisfactorily as an index to the molecularweight as any other procedure, subject to the above limitations, andespecially in the higher molecularzzf' weight range. If any difficultyis encountered in the manufacture of the esters as described in Part 3the stoichiometrical amount of acid or acid compound should be takenwhich corresponds to the indicated acetyl or hydroxylejgg pearing in thepatent previously mentioned. r,

PART 3' As previously pointed outthe present invention is concerned withacidic esters. obtained from the propylated derivativesdescribed in Part2, immediately preceding, and polycarboxy acids, particularly dicarboxyacids such as adipic acid, phthalic acid, or anhydride, succinic acid,diglycollic acid, sebacic. acid, azelaic acid, aconitic acid, maleicacid or anhydride, citraconie acid %5 or, anyhydride, maleic acid oranyhydride adducts as obtained by the Diels-Alder reaction fromproductsv such as maleic anhydride, and cyclopentadiene. Suchacidsshould be heat stable sothey are not decomposed duringesterificationf They may containas many as 36 carbon atoms as, forexample, the acids obtained by dimerization of unsaturated fatty acids,unsaturated monocarboxy fatty acids, or unsaturated monocarboxy acidshaving 18 carbon atoms. Reference to the acid in the hereto appendedclaims obviously includes the anhydrides or any other obviousequivalents. My preference, however. is. I

to use polycarboxy acids having 'notover 8 carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and glycols or other hydroxylated compounds is Wellknown. Needless to say, various compounds may be used such as the lowmolal ester, the anhydride, the acyl chloride, etc. However, for purposeof economy it .is customary to use either the acid or the anhydride. Aconventional procedure'is employed. On a laboratory scale one can employa resin pot of the kind described in U. S. Patent No. 2,499,370, datedMarch 7, 1950 to De Groote and Keiser, and particularly with one moreopening to permit the use of a porous spreaderv if hydrochloric acid gasis to be used as a catalyst. Such device or absorption spreader consistsof minutealundum thimbles which are connected to a glass tube. One canadd a .sulfonic acid such as para-toluene sulfonic acid as a catalyst.There is some objection to this because in some instances there is someevidence that this acid catalyst tends to decompose or rearrange heatoxypropylated compounds, and particularly likely to do so if theesterfiication temperature is too high. In the case of polycarboxy acidssuch as'diglycollic acid,

12 which is strongly acidic there is'no. needto add any catalyst. Theuse of hydrochloric, gas has one advantage over paratoluene sulfonicacid and that is that at the end of the reaction it can be removed byflushing out with nitrogen,

whereas there is no reasonably convenient means available of removingthe paratoluene sulfonic acid or othersulfonic acid employed.Ifhydrochloric acid is employed one need only pass the gas through at anexceedingly slow rate so as to keep the reaction mass acidic. Only atrace of acid need be present. I have employed hydrochloric acid gas orthe aqueous acid itself to eliminate the initial basic material. Mypreference, however, is to use no catalyst whatsoever and to' insurecomplete dryness of the diol as described in the final procedure justpreceding of Table 2.

The products obtained in Part 2 precedingmay contain a basic catalyst.As a general procedure I have added an amount of half-concentratedhydrochloricacid considerably in excess of What is required toneutralize the residual catalyst. The mixture is shaken thoroughly andallowed to'stand overnight. It is then filtered and refluxed with thexylene present until the water can be separatedin a phaseseparatingtrap. As soon as the product is substantially free from water thedistillation stops. This preliminary step can be carried out in theflask to be used for esterification. If there is any further depositionof sodium chloride during the reflux stage needless to say a secondfiltration may be required. In any event the neutral or slightly acidicsolution of the oxypropylated derivatives described in Part2 is thendiluted further with sufficient xylene, decalin, petroleum solvent, orthe. like, so that one has obtained approximately a 65% solution. Tothis solution there is added a polycarboxylated reactant as previouslydescribed, such as phthalic anhydride, succinic acid, or anhydride,diglycollic acid, etc. The mixture is refluxed until esterification iscomplete as indicated by elimination of water or drop in carboxyl value.Needless to say, if one produces a half-ester from an anhydride such asphthalic anhydride, no water is eliminated. However, if it is obtainedfrom diglycollic acid, for example, water is eliminated. All suchprocedures are conventional and have been so thoroughly described in theliterature that further consideration will be limited toa few examplesand a comprehensive table.

Other procedures for eliminating the basic residual catalyst, if any,can be employed. For example, the oxyalkylation can be conducted inabsence of a solvent or the solvent removed after oxypropylation. Suchoxypropylation end. product can then be acidified with just enoughconcentrated hydrochloric acid to just neutralize the residual basiccatalyst. To this product one can then add a small amount of anhydroussodium sulfate (sufficient in quantity to take up any water that ispresent) and then subject the mass to centrifugal force so as toeliminate the sodium sulfate and probably the sodium chloride formed.The clear somewhat viscous straw-colored amber liquid so obtained maycontain a small amount of sodium sulfate or sodium chloride, but, in anyevent, is perfectly acceptable for esteriflcation in the mannerdescribed.

It is to be pointed out that the products here described are notpolyesters in the sense that 13. there is a plurality of both diolradicals and acid radicals; the product is characterized by-having onlyone diol radical.

In some instances and,in fact, in many instances I have found that inspite of the dehydration methods employed above that a mere trace ofwater still comes through and that this 'mere trace of water certainlyinterferes with the acetyl or hydroxyl value determination, at leastwhen a number of conventional procedures are used and may retardesterification, particularly where there is no sulfonic acid orhydrochloric acid present as acatalyst. Therefore, I have preferred touse the following procedure: I have employed about 200 grams of the diolas described in Part 2, preceding; I have added about 60 grams ofbenzene, and then refluxed this mixture in the glass resin pot using aphase-separating trap until the benzene carried out all the waterpresent as water of solution or the equivalent. Ordinarily thisrefluxing temperature is apt to be in the neighborhood of 130 topossibly 150 C. When 1 all this water or moisture has been removed Ialso withdraw approximately 20 grams or a little less benzene and thenadd the required amount of the carboxy reactant and also about 150 gramsof a high boiling aromatic petroleum solvent. These solvents-are sold byvarious oil refineries and, as far as solvent effect act as if they were14 might just as well be allowed to remain. If the solvent is to beremoved by distillation, and particularly vacuum distillation, then thehigh boiling aromatic petroleum solvent might-well be replaced'by somemore expensive solvent, such as decalin or an alkylated decalin whichhas a rather definite or close range boiling point. The removal of thesolvent, of course, is purely a conventional procedure and requires noelaboration.

In the appended table Solvent #7-3, which appears in numerous instances,is a mixture of 7 volumes of the aromatic-petroleum solvent previouslydescribed and 3 volumes of benzene. .R'eference to Solvent #7 means theparticular petroleum solvent previously described in detail. This wasused, or a'similar mixture, in the manner previously described. A largenumber of the examples indicated employing decalin were repeated usingthismixture and particularly with the preliminary step of removing'allthe water. If one does not intend to remove the solvent my preference isto use the petroleum solvent-benzene mixture although obviously any ofthe other mixtures, such as decalin and xylene, can be employed.

The data included in the subsequent tables, i. e., Tables 2 and 3, areself-explanatory, and very complete and it is believed no furtherelaboration is necessary:

TABLE 2.

M01. Actual Wt. Amt. i Hy- Based Hyd decry] dmxyl 2 d PolycarboryRoactant Icxarboxy cactant V 1 A l l E H. O. a ue a (grs.)

112 220 512 202 Diglycolic Acid 7 106 1, 003 112 220 512 200 MaloicAnhyd7e. 56 127 890 198 Diglycolic Acid 55.5 37.4 79.5 1, 415 200 do -s7.s27.9 96.0 1,770 206 was v 31.0 27.9 96.0 1,770 203' M aleic A'nhyd 22.6

almost completely aromatic in character. Typical TABLE distillation datain the particular type I have em- 10 e 'an ound ver sati factoi" is thefollow- Amt Esteri- Time Of P a d f y a y Ex.N0. of 801- S01- ficationEsterifi- Water Out vent vent Temp, cation (cc.) 1. B. P., 142 c. ml,242 0. m 5 ml. 200 C. ml, 244 C.

#7-3 296 180 1 15.0. 10 ml, 209 C. ml., 248 C. #7-3 277 151 2 None 15ml., 215 c. ml, 252 0. ggg fig 3 20 ml., 216 C. ml., 252 C. #7-3 233 1373% 411: 25 ml, 220 C. 7-5 1211., 260 C. #7-3 226 131 2 None 30 ml., 225C. ml., 264 C. 35 m1. 230 C. ml., 270 C. T1

y e.) 1e proceduie for manufacturin the esters 40 ml., 234 0. ml., 2800. g

After this material is added, refluxing is continued. and, of course, isat a high temperature, to wit, about to C. If the carboxy reactant is ananhydride needless to say no water of reaction appears; if the carboxyreactant is an acid, Water of reaction should appear and should beeliminated at the above reaction temperature. If it is not eliminated Isimply separate out another 10 or 20 cc. of benzene by means of thephase-separating trap and thus raise the temperature to or 0., or evento 200 C., if need be. My preference is not to go above 200 C.

The use of such solvent is extremely satisfactory provided one does notattempt to remove the solvent subsequently except byvacuum distillationand provided there is no objection to a little residue. Actually, whenthese materials are used for a purpose such as demulsification thesolvent has been illustrated by preceding examples. If for any reasonreaction does not take place in a manner that is acceptable, attentionshould be directed. to the following details: (a) Recheck the hydroxylor acetyl value of the oxypropylated glycerol and use astoichiometrically equivalent amount of acid; (b) if the reaction doesnot proceed with reasonable speed either raise the temperaturesindicated or else extend the periodof time up to 12 or lfihours if needbe; (c) if necessary, use /2% of paratoluene sulfonic acidor some otheracid as a catalyst; (d) if the esterification does not produce a clearproduct a check should be made'to see if an inorganic salt such assodium chloride or sodium sulfate is not precipitating out. Such saltshould be eliminated, at least for exploration experimentation, and canbe removed by filtering. Everything else being equal as the size of themolecule increases the reactlve hydroxyl radical represents a smaller--fraction of. the entiresmolecule. and thus;more Y difficulty isinvolved in obtaining complete -esterification.

Even under the most carefully controlled conditions of oxypropylationinvolving comparatively low temperatures and long time of reaction thereare'formedcertain compounds whose composition is still obscure. Suchside reaction products can contribute a substantial proportion of thefinal cogeneric reaction mixture. Various suggestions. have been made asto the nature of these compounds, such as being cyclic polymers ofpropylene oxide, dehydration products with theappearance of a vinylradical, or isomers of propylene oxide or. derivatives thereof, 1. e.,of an aldehyde, ketone, or allyl alcohol. In some instances an attemptto react the stoichiometric amount of a polycarboxy acid with theoxypropylated derivative results in an excess of the carboxylatedreactant for the reason that apparently under conditions of reactionless reactive hydroxyl radicals are present then indicated by thehydroxyl value. Under such circumstances there is simply a residue ofthe carboxylic reactant which can be removed by filtration or, ifdesired, the esterification procedure can be released usinganappropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value and conventional procedureleaves much to be desired due either to the cogeneric materialspreviously referred to, or for thatimatte'r, the presence of anyinorganic salts or propylene oxide. Obviously this oxide shouldbeieliminated.

The solvent employed, if any, can be removed from the finished ester bydistillation andv particularly vacuum distillation. The final productsor liquids are generally light straw to light amber in color, and showmoderate viscosity. They can be bleached with bleaching clays, filteringchars, and the like. However, for the purpose of demulsification or thelike color is not a factor and decolorization is not justified.

In the above instances I have permitted the solvents to remain presentin the final reaction mass. In other instances I have followed the sameprocedure using decalin or a mixture of decalin or benzene in the samemanner and ultimately removed all the solvents by vacuum distillation.Appearances of the final products are much the same as the diols beforeesterification and in some instances were somewhat darker in color andhad a reddish cast and perhaps somewhat more viscous.

PART 4 Previous reference. has been made to the. fact that diols such aspolypropyleneglycol of approximately 2,000 molecular weight, forexample, have been esterified with dicarboxy acidsv and employedasdemulsifying agents. On first examination the difference between theherein described products and such comparable products appears toberather insignificant. In. fact, the

radical and a secondary alcohol radical.

' carboxy acid but in the diol.

Thedifference; of course, does not reside in the Momentarily an effortwill be made to emphasize certain things in regard to the structure of apolypropylene glycol, such as polypropylene glycol of a, 2000 molecularweight. Propylene glycol has a primary alcohol In this sense thebuilding unit which forms polypropylene glycols is not symmetrical.Obviously, then, polypropylene glycols can be obtained, at leasttheoretically, in which two secondary alcohol groups are united or asecondary alcohol group is united to a primary alcohol group,etherization being involved, of course, in each instance.

Usually no effort is made to differentiate between oxypropylation takingplace, for example, at the primary alcohol unit radical or the secondaryalcohol radical. Actually, when such products are obtained, such as ahigh molal pol-ypropylene glycol or the products obtained in the mannerherein described one does not obtain a single derivative such asI-IO(RO)nI-I in which n has one and only one value,.for instance, 14, 15or 16, or the like. Rather, one obtains a cogeneric mixture of closelyrelated or touching homologues. These materials invariably have highmolecular weights and cannot be separated from one another by any knownprocedure Without decomposition. The properties of such mixturerepresent the contribution of the various individual members of themixture. On a statistical basis, of course, n can be appropriatelyspecified. For practical purposes one need only consider theoxypropylation of a monohydric alcohol because in essence this issubstantially the mechanism involved. Even in such instances where oneis concerned with a monohydric reactant one cannot draw a single formulaand say that by following such procedure one can readily obtain or or ofsuch compound. However, in the case of at least monohydric initialreactants one can readily draw the formulas of a large number of.compounds which appear in some of the probable mixtures or can beprepared as components and mixtures which are manufacturedconventionally.

However, momentarily referring again to a monohydric initial reactant itis obviousv that if one selects'any such simple hydroxylated compoundand subjects such compound to oxyalkylation, such as oxyethylation, oroxpropylation, it becomes obvious that one is really producing a polymerof the alkylene oxides except for the terminal group. This isparticularly true where the amount of oxide added is comparativelylarge, for instance, 10, 20, 30, 40, or 50 units. If such compound issubjected to oxyethylation so as to introduce 30 units of ethyleneoxide, it is well known that one does not obtain a single constituentwhich, for the sake of convenience, may be indicated ,as R,O(C2H4O)30OH.Instead, one obtains a cogeneric mixture of closely related homologues,in which the formula may be shown as the following, RO(C2I-I4O)11H,wherein n, as far as the statistical average goes, is 30, but theindividual members present in significant amount may vary from instanceswhere n has a value of 25, and perhaps less, to a point where n mayrepresent 35 or more. Such mixture is, as s tated,'a cogeneric closelyrelated series of touching homologous compounds. Considerableinvestigation has been made in regard to the distribution curves forlinear polymers. Attention is directed to the article entitledFundamental principles 17 of condensation polymerization, by Flory,which appeared in Chemical Reviews, volume 39, No. Lpage 137.

Unfortunately, as has been pointed out by Flory and other investigators,there is no satisfactory method, based on either experimental ormathematical examination, of indicating the exact proportion of thevarious members of touching homologous series which appear in cogenericcondensation products of the kind described. This means that from thepractical standpoint, i. e., the ability to describe how to make theproduct under consideration and how to repeat such production time aftertime without difiiculty, it is necessary to resort to some other methodof description, or else consider the value of n, in formulassuch asthose which have appeared previously and which appear in the claims, asrepresenting both individual constituents in which n has a singledefinite value,

and also with the understanding that n represents the averagestatistical value based on the assumption of completeness of reaction.

This may be illustrated as follows: Assume that in any particularexample the molal ratio of the propylene oxide to the diol is 15 to 1.Actually, one obtains products in which n probably varies from to 20,perhaps even further. The average value, however, is 15, assuming, aspreviously stated, that the reaction is complete. The product describedby the formula is best described also in terms of method of manufacture.

However, in the instant situation it becomes obvious that if an ordinaryhigh molal propyleneglycol is compared to strings of White beads ofvarious lengths, the diols herein employed as intermediates arecharacterized by the presence of a black bead, i. e., a radical whichcorresponds to the glycerol ether of diethylene glycol monoethyl etheras previously described, i. e. the radical o csmocmomo 011201120 03115Furthermore, it becomes obvious now that one has a nonsymmetricalradical in the majority of cases for reason that in the cogenericmixture going back to the original formula n and 11. are usually notequal. For instance, if one introduces moles of propylene oxide, 1:. and11. could not be equal, insofar that the nearest approach to equality iswhere the value of n is 7 and n is 8. However, even in the case of aneven number such as 20, 30, 40 or 50, it is also obvious that n and nwill not be equal in light of what has been said previously. Both sidesof the molecule are not going to grow with equal rapidity, i. e., to thesame size. Thus the diol herein employed is diiferentiated frompolypropylene diol 2000, for example, in that (a) it carries aheterogeneous unit, i. e., a unit other than a propylene glycol orpropylene oxide u-nit, (1)) such unit is off center, and (c) the effectof, that unit, of course, must have some eflect in the range with whichthe linear molecules can be drawn together by hydrogen binding or Vander Waals forces, or whatever else may be involved.

What has been said previously can be emphasized in the following manner.It has been pointed out previously that in the last formula immediatelypreceding, n or n could be zero.

Under the conditions of manufacture as described in Part 2 it isextremely unlikely that n is ever zero.- However, such compounds can beprepared readily with comparatively little difficulty by resorting to ablocking effect or reaction. For instance, if the diol is esterifiedwith a low molal acid such as acetic acid mole'for mole and such productsubjected to oxyalkylation using a catalyst, such as sodium methylateand guarding against the presence of any water, it becomes evident thatall the propylene oxide introduced, for instance 15 to molecule perpolyhydric alcohol necessarily must enter at one side only. If suchproduct is then saponified so as to decompose the acetic acid ester andthen acidified so as to liberate the water-soluble acetic acid and thewater-insoluble diol a separation can be made and such diol thensubjected to esterification as described in Part 3, preceding. Suchesters, of course, actually represent products where either n or n iszero. Also intermediate procedures can be employed, i. e., following thesame esterification step after partial oxypropylation. For instance, onemight oxypropylate With one-half the ultimate amount of propylene oxideto be used and then stop the reaction. One could then convert thispartial oxypropylated intermediate into an ester by reaction of one moleof acetic acid with one mole of a diol. This ester could then beoxypropylated with all the remaining propylene oxide. The final productso obtained could be saponified and acidified so as to eliminate thewater-soluble acetic acid and free the obviously unsymmetrical diolwhich, incidentally, should also be kerosene-soluble.

From a practical standpoint I have found no advantage in going to thisextra step but it does emphasize the difference in structure between theherein described diols employed as intermediates and high molalpolypropylene glycol, such as polypropylene glycol 2000.

The most significant fact in this connection is the following. Theclaims hereto attached are directed to a very specific compound, i. e.,onederived by the oxypropylation of the glycerol ether of ethyleneglycol monobutyl ether. In addition to this glycol ether a large numberof other glycol others as, for example, ethylene glycol monomethylether, ethylene glycol ethylbutyl ether, ethylene glycol monophenylether, ethylene glycol monobenzyl ether, diethylene glycol monomethylether, diethylene glycol monoethyl ether, and diethylene glycolmonobutyl ether are available.

I have taken each and every one of these glycol ethers and, as a matterof fact, a large number of others, subjected them to reaction withglycide and then oxypropylated the compounds and esterified them in themanner described in the instant application. I have tested all theseproducts for demulsification and at least to date I have not foundanother analogous compound equally effective for demulsification andalso for certain other applications in which surface activity isinvolved. At the moment, based on this knowledge, this particularcompound appears unique for reasons not understood.

PART 5 Conventional demulsifying agents employed in the treatment of oilfield emulsions are used as such, or after dilution with any suitablesolvent, such as water, petroleum hydrocarbons, such as benzene,toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols,particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol,denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octylalcohol, 6110., may be employed as diluents. Miscellaneous solvents suchas pine oil, carbon tetrachloride, sulfur dioxide extract obtained inthe refining of petroleum, etc., may be employed as diluents. Similarly,the material or materials employed as the demulsifying agent of myprocess may be admixed with one or more of the solvents customarily usedin connection with conventional demulsifying agents. Moreover, saidmaterial or materials may be used alone or in admixture with othersuitable well-known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in awater-soluble form, or in an oil-soluble form, or in a form exhibitingboth oiland water-solubility. Sometimes they may be used in a form whichexhibits relatively limited oil-solubility. However, since such reagentsare frequently used in a ratio of 1 to 10,000 or 1 to 20,000, or 1 to30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice,such an apparent insolubility in oil and water is not significantbecause said reagents undoubtedly have solubility within suchconcentrations. This same. fact is true in regard to the material ormaterials employed as the demulsifying agent of my process.

In practicing my process for resolving petroleum emulsions of thewater-in-oil type, a treating agent or demulsifying agent of the kindabove described is brought into contact with or caused to act upon theemulsion to be treated, in any of the various apparatus now generallyused to resolve or break petroleum emulsions with a chemical reagent,the above procedure being used alone or in combination with otherdemulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in atank and conduct a batch treatment type of demulsification procedure torecover clean oil. In this procedure the emulsion is admixed with thedemulsifier, for example by agitating the tank of emulsion and slowlydripping demulsifier into the emulsion. In some'cases mixing is achievedby heating the emulsion while dripping in the demulsifier, dependingupon the convection currents in the emulsion to produce satisfactoryadmixture. In a third modification of this type of treatment, acirculating pump withdraws emulsion from, c. g., the bottom of the tank,and reintroduces it into the top of the tank, the demulsifier beingadded, for example, at the suction side of said circulating pump.

In a second type of treating procedure, the demulsifier is introducedinto the well fluids at the well-head or at some point between thewellhead and the final oil storage tank, by means of an adjustableproportioning mechanism or proportioning pump. Ordinarily the flow offluids through the subsequent lines and fittings suffices to produce thedesired degree of mixing of demulsifier and emulsion, although in someinstances additional mixing devices may be introduced into the flowsystem. In this general procedure, the system may include variousmechanical devices for withdrawing free water, separating entrainedwater, or accomplishing quiescent settling of the chemicalized emulsion.Heating devices may likewise be incorporated in any of the treatingprocedures described herein.

A. third type of application (down-the-hole) of demulsifier to emulsionis to introducethe demulsifier either periodically or continuously in 20diluted or undiluted form into the well'andto allow it to come to thesurface with the well fluids, and then to flow the chemicalized emulsionthrough any desirable surface equipment,

such as employed in the other treating proceportion of emulsion,admixing the chemical and emulsion either through natural flow orthrough special apparatus, with or without the application of heat, andallowing the mixture to stand quiescent until the undesirable watercon'tent of theemulsion separates and settles from the'mass.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted orundiluted) is placed at the well-head where the effluent liquidsleavethe well. This reservoir or container, which may vary from 5gallons to 50 gallons for convenience, is connected to a proportioningpump which'i'njects the demulsifier drop-wise into the fiuids leavingthe well. Such chemicalized fluids pass through the flowline into asettling tank. The settling tank consists of a tank of any convenientsize, for instance, one which will hold amounts of fiuid produced in 4to 24 hours (500 barrels to 2000 barrels capacity), and in which thereis a perpendicular conduit from the top of the tank to almost the verybottom so as to permit the incoming fluids to pass from the top of thesettling tank to the bottom, so that such incoming fluids do not disturbstratification which takes place during the course of demulsification.The settling tank has two outlets, one being below the water level todrain oil the water resulting from demulsification or accompanying theemulsion as free water, the other being an oil outlet at the top topermit the passage of dehydrated oil to a second tank, being a storagetank, which'holds pipeline or dehydrated oil. If desired, the conduit orpipe which serves to carry the fluids from the well to the settling tankmay include a section of pipe with baffles to serve as a mixer, toinsure thorough distribution of the demulsifier throughout the fluids,or a heater for raising the temperature of the fluids to some convenienttemperature, for instance, to F., or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as tofeed a comparatively large ratio of demulsifier, for instance, 1:5,000.As soon as a complete break or satisfactory demulsification is obtained,the pump is regulated until experience shows that the amount ofdemulsifier being added is just sufficient to produce clean ordehydrated oil. The amount being fed at such stage is usually 1:10.,000,1:l 5,000, 1:20,000, or the like.

In many instances the oxyalkylated products herein specified asdemulsifiers can'be conveniently used without dilution. However, aspreviously noted, they may be diluted as desired with any suitablesolvent. For instance, by mixing 75 parts by weight of an oxyalkylatedderivative, for example, the product of Example 50 with 15 parts byweight of xylene and 10 parts by weight of isopropyl alcohol, an excel-21 lent demulsifier is obtained. Selection of the solvent will vary,depending upon the solubility characteristics of the oxyalkylatedproduct, and of course will be dictated in part by economicconsiderations, i. e., cost.

As noted above, the products herein described may be used not only indiluted form, but also may be used admixed with some other chemicaldemulsifier. A mixture which illustrates such combination is thefollowing:

Oxyalkylated derivative, for example, the product of Example 50, 20%;

A cyclohexylamine salt of a polypropylated naphthalene monosulfonicacid, 24%;

An ammonium salt of a polypropylated naphthalene mono-sulfonic acid,24%;

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%.

A high-boiling aromatic petroleum solvent, 15%;

Isopropyl alcohol,

The above proportions are all weight percents.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent, is:

1. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products, said hydrophile syntheticproducts being characterized by the following formula in which R is theradical of a glycerol ether of diethylene glycol monoethyl ether; n andn are numerals with the proviso that n and n equal a sum varying from to80, and 'n" is a whole number not over 2, and R is the radical of thepolybasic acid COOH in which n" has its previous significance, and withthe further proviso that the parent dihydroxylated compound prior toesterification be water-insoluble.

2. A process for breaking petroleum emulsions of the water-in-oiltypecharacterized by subjecting the emulsion to the action of ademulsifier including hydrophile synthetic products; said hydrophilesynthetic products being characterized by the following formula I (HO 0CLWREJ(OCaHe)nORO(CsHoO)n R(C 00m.

in which R is the radical of a glycerol ether of diethylene glycolmonoethyl ether; 12 and n are numerals with the proviso that n and 11.equal a sum varying from 15 to 80, and n" is a whole number not over 2,and R is the radical of the polybasic acid in which n" has its previoussignificance, and with the further proviso that the parentdihydroxylated compound prior to esterification be water-insoluble, andat least kerosene-dispersible.

3. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being characterized by the following formula 0 0 (HOOC),.R&(OCaHe)OR'O(0:4HaO).u R(COOH)n" in which R is the radical of aglycerol ether of diethylene glycol monoethyl ether; 12 and n arenumerals with the proviso that 1L and 11. equal a sum varying from 15 to80, and n" is a whole number not over 2, and R is the radical of thepolybasic :acid

COOH in which R is the radical of a glycerol ether of dipropylene glycolmonoethyl ether; 11. and n are numerals with the proviso that n and 11.equal :a sum varying from 15 to 80, and R is the radical of thedicarboxy acid COOH COOH said dicarboxy acid having not over 8 carbonatoms; and with the further proviso that the parent dihydroxylatedcompound prior to esterification be water-insoluble and at leastkerosenedispersible.

5. The process of claim 4 wherein the dicarboxy acid is phthalic acid.

6. The process of claim 4 wherein the dicarboxy acid is maleic acid.

7. The process of claim 4 wherein the dicarboxy acid is succinic acid.

8. The process of claim 4 wherein the dicarboxy acid is citraconic acid.

9. The process of claim 4 wherein the dicarboxy acid is diglycolic acid.

MELVIN DE GROOTE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Blair Aug. '7, 1951 Number

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPECHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIERINCLUDING HYDROPHILE SYNTHETIC PRODUCTS, SAID HYDROPHILE SYNTHETICPRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA